Capillary electrophoresis apparatus and electrophoresis method

Abstract

An object of the present invention is to provide a capillary electrophoresis apparatus in which simultaneity can be ensured between sensitivity and data acquisition to decrease a pull-up signal while spectral data acquisition is eliminated in each capillary exchange. The invention relates to a capillary electrophoresis apparatus characterized in that a multi-bandpass filter is provided in an optical detection system. In one aspect of the invention, a signal detection area of a two-dimensional detector is divided into plural regions corresponding to wavelength transmission regions of the multi-bandpass filter. An integrated value of the fluorescence spectrum signal is determined in the region including a fluorescence spectrum peak of an analysis sample in the plural regions. The analysis is performed with the integrated value.

1. A capillary electrophoresis apparatus having:
 a capillary; 
 an optical irradiation system which irradiates the capillary with excitation light; and 
 an optical detection system comprising:
 a wavelength dispersion device configured to disperse fluorescent light from the capillary along a direction perpendicular to the capillary axis, 
 a two-dimensional detector configured to detect a fluorescence spectrum image acquired from the wavelength dispersion device, and 
 a multi-bandpass filter having a plurality of predetermined discontinuous wavelength transmission regions, 
 
 wherein: 
 the multi-bandpass filter cuts off the fluorescent light having a wavelength longer than a predetermined long-wavelength edge and the fluorescent light having a wavelength shorter than a predetermined short-wavelength edge, 
 the multi-bandpass filter has at least one discontinuous cutoff region between the predetermined long-wavelength edge and the predetermined short-wavelength edge, 
 the two-dimensional detector is a two-dimensional charged coupled-device device (CCD) camera configured to form images from the capillary in the wavelength dispersion direction and the capillary axis direction, the capillary axis direction being orthogonal relative to the wavelength dispersion direction, 
 the optical detection system calculates an integrated value of a signal of the fluorescence spectrum for each of the wavelength transmission regions of the multi-bandpass filter, and 
 excitation light irradiating the capillary propagates in the capillary axis direction. 
 
     
     
       2. A capillary electrophoresis apparatus according to  claim 1 , wherein a signal detection area of the two-dimensional detector is divided into a plurality of regions corresponding to the wavelength transmission regions of the multi-bandpass filter. 
     
     
       3. A capillary electrophoresis apparatus according to  claim 2 , wherein an integrated value of a signal of the fluorescence spectrum is determined in a region including a fluorescence spectrum peak of a sample in the plurality of regions. 
     
     
       4. A capillary electrophoresis apparatus according to  claim 2 , wherein the integrated value of the signal of the fluorescence spectrum is determined in each of the plurality of regions, and it is judged that the region where the integrated value becomes the maximum is the region where the fluorescence spectrum peak exists. 
     
     
       5. A capillary electrophoresis apparatus according to  claim 1 , wherein the multi-bandpass filter includes a plurality of notch filters and one bandpass filter. 
     
     
       6. A capillary electrophoresis apparatus according to  claim 1 , wherein the optical irradiation system irradiates the capillary with the excitation light from a direction along an axis line of the capillary or a direction in which the excitation light is inclined at a predetermined angle with respect to the axis line of the capillary. 
     
     
       7. A capillary electrophoresis apparatus according to  claim 1 , wherein the optical irradiation system has a light emitting diode which is of an excitation light source. 
     
     
       8. An analysis apparatus having:
 a capillary; 
 an optical irradiation unit which irradiates the capillary with excitation light; 
 an optical detection system which has a wavelength dispersion device, a multi-bandpass filter, and a two-dimensional detector, the wavelength dispersion device dispersing fluorescent light from the capillary along a direction perpendicular to the capillary axis, the multi-bandpass filter transmitting only a plurality of predetermined discontinuous wavelength transmission regions in fluorescence spectra acquired from the wavelength dispersion device, the two-dimensional detector detecting a fluorescence spectrum image transmitted through the multi-bandpass filter, 
 wherein: 
 a sample is analyzed from a fluorescence spectrum of the sample detected by the optical detection unit, 
 the multi-bandpass filter cuts off the fluorescent light having a wavelength longer than a predetermined long-wavelength edge and the fluorescent light having a wavelength shorter than a predetermined short-wavelength edge, and the multi-bandpass filter has at least one discontinuous cutoff region between the predetermined long-wavelength edge the predetermined short-wavelength edge, 
 the two-dimensional detector is a two-dimensional charged coupled-device device (CCD) camera configured to form images from the capillary in the wavelength dispersion direction and the capillary axis direction, the capillary axis direction being orthogonal relative to the wavelength dispersion direction, 
 optical detection system calculates an integrated value of a signal of the fluorescence spectrum for each of the wavelength transmission regions of the multi-bandpass filter, and 
 excitation light irradiating the capillary propagates in the capillary axis direction. 
 
     
     
       9. An analysis apparatus according to  claim 8 , wherein a signal detection area of the two-dimensional detector is divided into a plurality of regions corresponding to wavelength transmission regions of the multi-bandpass filter. 
     
     
       10. An analysis apparatus according to  claim 8 , wherein an integrated value of a signal of the fluorescence spectrum is determined in a region including a fluorescence spectrum peak of a sample in the plurality of regions. 
     
     
       11. A capillary electrophoresis method in which a sample is electrophoresed in a capillary, the capillary is irradiated with excitation light, fluorescent light from the capillary is dispersed along a direction perpendicular to the capillary axis to generate a fluorescence spectrum, an image of the fluorescence spectrum is detected by a two-dimensional detector, and the sample is analyzed based on the detection result,
 wherein: 
 the two-dimensional detector detects the image of the fluorescence spectrum after the fluorescence spectrum is transmitted through a multi-bandpass filter having a plurality of predetermined discontinuous wavelength transmission regions, 
 the two-dimensional detector is a two-dimensional charged coupled-device device (CCD) camera configured to form images from the capillary in the wavelength dispersion direction and the capillary axis direction, the capillary axis direction being orthogonal relative to the wavelength dispersion direction, 
 the multi-bandpass filter cuts off the fluorescent light having a wavelength longer than a predetermined long-wavelength edge and the fluorescent light having a wavelength shorter than a predetermined short-wavelength edge, 
 the multi-bandpass filter has at least one discontinuous cutoff region between the predetermined long-wavelength edge and the predetermined short-wavelength edge, and 
 wherein an optical detection system calculates an integrated value of a signal of the fluorescence spectrum for each of the wavelength transmission regions of the multi-bandpass filter, and 
 excitation light irradiating the capillary propagates in the capillary axis direction. 
 
     
     
       12. A capillary electrophoresis method according to  claim 11 ,
 wherein a signal detection area of the two-dimensional detector is divided into a plurality of regions corresponding to wavelength transmission regions of the multi-bandpass filter. 
 
     
     
       13. A capillary electrophoresis method according to  claim 11 ,
 wherein an integrated value of a signal of the fluorescence spectrum is determined in a region including a fluorescence spectrum peak of an analysis sample in the plurality of regions. 
 
     
     
       14. A capillary electrophoresis method according to  claim 11 , wherein the integrated value of the signal of the fluorescence spectrum is determined in each of the plurality of regions, and it is judged that the region where the integrated value becomes the maximum is the region where the fluorescence spectrum peak exists. 
     
     
       15. A capillary electrophoresis apparatus having:
 a capillary; 
 an optical irradiation system which irradiates the capillary with excitation light; and 
 an optical detection system which includes a wavelength dispersion device and a two-dimensional detector, the wavelength dispersion device dispersing fluorescent light from the capillary along a direction perpendicular to the capillary axis, the two-dimensional detector detecting a fluorescence spectrum image acquired from the wavelength dispersion device, 
 wherein: 
 the optical detection system has a multi-bandpass filter having a plurality of predetermined discontinuous wavelength transmission regions, 
 the multi-bandpass filter has at least one notch filter and at least one bandpass filter, 
 the bandpass filter cutting off the fluorescent light having a wavelength longer than a predetermined long-wavelength edge and the fluorescent light having a wavelength shorter than a predetermined short-wavelength edge, 
 the at least one notch filter and the at least one bandpass filter are positioned sequentially along an axis, 
 the two-dimensional detector is a two-dimensional charged coupled-device device (CCD) camera configured to form images from the capillary in the wavelength dispersion direction and the capillary axis direction, the capillary axis direction being orthogonal relative to the wavelength dispersion direction, 
 the optical detection system calculates an integrated value of a signal of the fluorescence spectrum for each of the wavelength transmission regions of the multi-bandpass filter, and 
 excitation light irradiating the capillary propagates in the capillary axis direction. 
 
     
     
       16. A capillary electrophoresis apparatus according to  claim 15 , wherein a signal detection area of the two-dimensional detector is divided into a plurality of regions corresponding to the wavelength transmission regions of the multi-bandpass filter. 
     
     
       17. A capillary electrophoresis apparatus according to  claim 16 , wherein an integrated value of a signal of the fluorescence spectrum is determined in a region including a fluorescence spectrum peak of a sample in the plurality of regions. 
     
     
       18. A capillary electrophoresis apparatus according to  claim 16 , wherein the integrated value of the signal of the fluorescence spectrum is determined in each of the plurality of regions, and it is judged that the region where the integrated value becomes the maximum is the region where the fluorescence spectrum peak exists. 
     
     
       19. A capillary electrophoresis apparatus according to  claim 15 , wherein the optical irradiation system irradiates the capillary with the excitation tight from a direction along an axis line of the capillary or a direction in which the excitation light is inclined at a predetermined angle with respect to the axis line of the capillary. 
     
     
       20. A capillary electrophoresis apparatus according to  claim 15 , wherein the optical irradiation system has a light emitting diode which is of an excitation light source. 
     
     
       21. An analysis apparatus having: a capillary;
 an optical irradiation system which irradiates the capillary with excitation light; 
 an optical detection unit which has a wavelength dispersion device, a multi-bandpass filter, and a two-dimensional detector, the wavelength dispersion device dispersing fluorescent light from the capillary along a direction perpendicular to the capillary axis, the multi-bandpass filter transmitting only a plurality of predetermined discontinuous wavelength transmission regions in fluorescence spectra acquired from the wavelength dispersion device, the two-dimensional detector detecting a fluorescence spectrum image transmitted through the multi-bandpass filter, 
 wherein: 
 a sample is analyzed from a fluorescence spectrum of the sample detected by the optical detection unit, 
 the multi-bandpass filter has at least one notch filter and at least one bandpass filter, 
 the bandpass filter cutting off the fluorescent light having a wavelength longer than a predetermined long-wavelength edge and the fluorescent light having a wavelength shorter than a predetermined short-wavelength edge, 
 the at least one notch filter and the at least one bandpass filter are positioned sequentially along an axis, 
 the two-dimensional detector is a two-dimensional charged coupled-device device (CCD) camera configured to form images from the capillary in the wavelength dispersion direction and the capillary axis direction, the capillary axis direction being orthogonal relative to the wavelength dispersion direction, 
 the optical the detection system calculates an integrated value of a signal of the fluorescence spectrum for each of the wavelength transmission regions of the multi-bandpass filter, and 
 excitation light irradiating the capillary propagates in the capillary axis direction. 
 
     
     
       22. An analysis apparatus according to  claim 21 , wherein a signal detection area of the two-dimensional detector is divided into a plurality of regions corresponding to wavelength transmission regions of the multi-bandpass filter. 
     
     
       23. An analysis apparatus according to  claim 21 , wherein an integrated value of a signal of the fluorescence spectrum is determined in a region including a fluorescence spectrum peak of a sample in the plurality of regions. 
     
     
       24. A capillary electrophoresis method in which a sample is electrophoresed in a capillary, the capillary is irradiated with excitation light, fluorescent light from the capillary is dispersed to generate a fluorescence spectrum, an image of the fluorescence spectrum is detected by a two-dimensional detector, and the sample is analyzed based on the detection result,
 wherein: 
 the two-dimensional detector detects the image of the fluorescence spectrum after the fluorescence spectrum is transmitted through a multi-bandpass filter having a plurality of discontinuous wavelength transmission regions, 
 the multi-bandpass filter has at least one notch filter and at least one bandpass filter, 
 the bandpass filter cutting off the fluorescent light having a fluorescent wavelength longer than a predetermined long-wavelength edge and the fluorescent light having a wavelength shorter than a predetermined short-wavelength edge, 
 the at least one notch filter and the at least one bandpass filter are positioned sequentially along an axis, 
 the two-dimensional detector is a two-dimensional charged coupled-device device (CCD) camera configured to form images from the capillary in the wavelength dispersion direction and the capillary axis direction, the capillary axis direction being orthogonal relative to the wavelength dispersion direction, 
 an optical detection system calculates an integrated value of a signal of the fluorescence spectrum for each of the wavelength transmission regions of the multi-bandpass filter, and 
 excitation light irradiating the capillary propagates in the capillary axis direction. 
 
     
     
       25. A capillary electrophoresis method according to  claim 24 , wherein a signal detection area of the two-dimensional detector is divided into a plurality of regions corresponding to wavelength transmission regions of the multi-bandpass filter. 
     
     
       26. A capillary electrophoresis method according to  claim 24 , wherein an integrated value of a signal of the fluorescence spectrum is determined in a region including a fluorescence spectrum peak of an analysis sample in the plurality of regions. 
     
     
       27. A capillary electrophoresis method according to  claim 24 , wherein the integrated value of the signal of the fluorescence spectrum is determined in each of the plurality of regions, and it is judged that the region where the integrated value becomes the maximum is the region where the fluorescence spectrum peak exists.